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TK880 vs TK880H


Question

Posted

Are the only differences (besides the obvious larger heat sink of the 880H) on these two radios just the RF MOSFET Amplifier Module and the extra voltage regulator on the 880?  Am I missing something else?

I bought a non working 880H and was able to get it to power on by replacing a diode, a capacitor and the one voltage regulator, but there is no audio and no power coming from the antenna, even though it is transmitting and receiving.  I started looking at the two and those are the only differences that I see. Seems weird that the lower power 880 has the 2 voltage regulators where the 880H just has the one. Also, any idea why the 880 has no audio and no power coming from the antenna wire (I tried external speaker and had swr?watt meter attached to antenna wire with zero SWR and zero watt output - even though when I transmit, it is being picked up on an ht nearby) Another thing too, even though the display works on the 880H, the LED's don't

Also, don't mind those extra wires. I was testing these radios as RX radios in a portable repeater

880_Volt_reg.jpg

880vs880H.jpg

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Posted
7 minutes ago, Flameout said:

Even though these radios are listed at 450-490 MHz, they can still be programmed in the 420-450 MHz 70 cm bands?

If someone with a service manual tweaked various inductors and potentiometers, they may have shifted the optimal transmit frequency down to 70cm. It's only a 30MHz change to go from centered on 470MHz to centered on 440MHz.

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Posted

Ok, fleetsync programming points out that they are not realigned for ham bands.

And yes, type "-1" radios can work on the upper portion of 70cm band, it is where repeaters are. I did not realign mine, they work just fine, without any distortion. Audio reports are good. I never got around to actually measure the power output on different sections of 70cm, one day I will do that. KPG-49D will throw up the prompt that frequency is out of band, but it will still write it into the radio and radio will tune to it.

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Posted
5 hours ago, KAF6045 said:

If someone with a service manual tweaked various inductors and potentiometers, they may have shifted the optimal transmit frequency down to 70cm. It's only a 30MHz change to go from centered on 470MHz to centered on 440MHz.

Yes, I think there is an article on RepeaterBuilder about how to realign TK880 to 70cm, I remember reading it. But I never did it to my radios, and they do work on the repeater section on 70cm band, and can be programmed with the unmodified/unhacked KBG-49D.

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